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Why is there no String.Empty in Java?
I understand that every time I type the string literal "" , the same String object is referenced in the string pool.
11 An...
MySQL Error 1215: Cannot add foreign key constraint
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I'm guessing that Clients.Case_Number and/or Staff.Emp_ID are not exactly the same data type as Clients_has_Staff.Clients_Case_Number and Clients_has_Staff.Staff_Emp_ID.
Perhaps the columns in the parent tables are INT UNSIGNED?
They need to be exactly the same...
How to get ID of the last updated row in MySQL?
...T 1;
SELECT @update_id;
EDIT by aefxx
This technique can be further expanded to retrieve the ID of every row affected by an update statement:
SET @uids := null;
UPDATE footable
SET foo = 'bar'
WHERE fooid > 5
AND ( SELECT @uids := CONCAT_WS(',', fooid, @uids) );
SELECT @uids;
This w...
How to get the cuda version?
Is there any quick command or script to check for the version of CUDA installed?
19 Answers
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Is there a REAL performance difference between INT and VARCHAR primary keys?
...AR as the primary key for reference lists (think US States, Country Codes) and a coworker won't budge on the INT AUTO_INCREMENT as a primary key for all tables.
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Ruby: require vs require_relative - best practice to workaround running in both Ruby =1.
What is the best practice if I want to require a relative file in Ruby and I want it to work in both 1.8.x and >=1.9.2?
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How to store arrays in MySQL?
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The proper way to do this is to use multiple tables and JOIN them in your queries.
For example:
CREATE TABLE person (
`id` INT NOT NULL PRIMARY KEY,
`name` VARCHAR(50)
);
CREATE TABLE fruits (
`fruit_name` VARCHAR(20) NOT NULL PRIMARY KEY,
`color` VARCHAR(20),
`price` INT
)...
Why does the indexing start with zero in 'C'?
Why does the indexing in an array start with zero in C and not with 1?
16 Answers
16
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What is stability in sorting algorithms and why is it important?
...ms are stable by nature like Insertion sort, Merge Sort, Bubble Sort, etc. And some sorting algorithms are not, like Heap Sort, Quick Sort, etc.
Background: a "stable" sorting algorithm keeps the items with the same sorting key in order. Suppose we have a list of 5-letter words:
peach
straw
appl...
Comparing Dates in Oracle SQL
...C, doesn't necessarily mean December. It depends on your NLS_DATE_LANGUAGE and NLS_DATE_FORMAT settings. To ensure that your comparison with work in any locale you can use the datetime format model MM instead
The year '95 is inexact. You know you mean 1995, but what if it was '50, is that 1950 or 2...